Open Access2015/16 I‐ MOVE /I‐ MOVE + multicentre case‐control study in Europe: Moderate vaccine effectiveness estimates against influenza A(H1N1)pdm09 and low estimates against lineage‐mismatched influenza B among children
Author(s) -
Kissling Esther,
Valenciano Marta,
Pozo Francisco,
Vilcu AnaMaria,
Reuss Annicka,
Rizzo Caterina,
Larrauri Amparo,
Horváth Judit Krisztina,
Brytting Mia,
Domegan Lisa,
Korczyńska Monika,
Meijer Adam,
Machado Ausenda,
Ivanciuc Alina,
Višekruna Vučina Vesna,
Werf Sylvie,
Schweiger Brunhilde,
Bella Antonino,
Gherasim Alin,
Ferenczi Annamária,
Zakikhany Katherina,
O′Donnell Joan,
ParadowskaStankiewicz Iwona,
Dijkstra Frederika,
Guiomar Raquel,
Lazar Mihaela,
Kurečić Filipović Sanja,
Johansen Kari,
Moren Alain
Publication year - 2018
Publication title -
influenza and other respiratory viruses
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.743
H-Index - 57
eISSN - 1750-2659
pISSN - 1750-2640
DOI - 10.1111/irv.12520
Subject(s) - medicine , influenza vaccine , influenza a virus , influenza like illness , vaccination , virology , immunology , virus
Background During the 2015/16 influenza season in Europe, the cocirculating influenza viruses were A(H1N1)pdm09 and B/Victoria, which was antigenically distinct from the B/Yamagata component in the trivalent influenza vaccine. Methods We used the test‐negative design in a multicentre case‐control study in twelve European countries to measure 2015/16 influenza vaccine effectiveness ( VE ) against medically attended influenza‐like illness ( ILI ) laboratory‐confirmed as influenza. General practitioners swabbed a systematic sample of consulting ILI patients and a random sample of influenza‐positive swabs was sequenced. We calculated adjusted VE against influenza A(H1N1)pdm09, A(H1N1)pdm09 genetic group 6B.1 and influenza B overall and by age group. Results We included 11 430 ILI patients, of which 2272 were influenza A(H1N1)pdm09 and 2901 were influenza B cases. Overall VE against influenza A(H1N1)pdm09 was 32.9% (95% CI : 15.5‐46.7). Among those aged 0‐14, 15‐64 and ≥65 years, VE against A(H1N1)pdm09 was 31.9% (95% CI : − 32.3 to 65.0), 41.4% (95% CI : 20.5‐56.7) and 13.2% (95% CI : − 38.0 to 45.3), respectively. Overall VE against influenza A(H1N1)pdm09 genetic group 6B.1 was 32.8% (95% CI : − 4.1 to 56.7). Among those aged 0‐14, 15‐64 and ≥65 years, VE against influenza B was − 47.6% (95% CI : − 124.9 to 3.1), 27.3% (95% CI : − 4.6 to 49.4) and 9.3% (95% CI : − 44.1 to 42.9), respectively. Conclusions Vaccine effectiveness ( VE ) against influenza A(H1N1)pdm09 and its genetic group 6B.1 was moderate in children and adults, and low among individuals ≥65 years. Vaccine effectiveness ( VE ) against influenza B was low and heterogeneous among age groups. More information on effects of previous vaccination and previous infection is needed to understand the VE results against influenza B in the context of a mismatched vaccine.